Southwest is often times competitive; often times it is not. They're profitable, however, and that's what counts in this airline business. If somebody has a lower airfare from GEG to PHX, then that's great-- it's the marketplace in action.
I remember very well when Southwest was the redheaded stepchild and was looked down upon. Now that this has been upended and they're sitting on top, it's fun to watch people snipe away at the little LUV airline.